Method making use of several times of flashes to detect distance and luminance of target

Abstract

A method making use of several times of flashes to detect the distance and luminance of a target is proposed. The method applies to an image capturing device. First, a flashlight installed in the image capturing device emits out a flash to illuminate the target. A flash response value reflected by the target is then received. Next, a distance value and a luminance value corresponding to the target are calculated according to the flash response value. Subsequently, whether the flashlight emits out a flash of an appropriate intensity is determined according to the distance value and the luminance value. If the flashlight does not emit out a flash of an appropriate intensity, the step of emitting out a flash to illuminate the target by the flashlight of the image capturing device is repeated.

I claim:  
     
         1 . A method making use of several times of flashes to detect the distance and luminance of a target, said method applying to an image capturing device, said method comprising the steps of: 
 (a) emitting out a flash to illuminate said target by a flashlight of said image capturing device;    (b) calculating and determining whether said flashlight emits out a flash of an appropriate intensity according to a flash response value;    (c) jumping back to said step (a) if said flashlight does not emit out a flash of an appropriate intensity.    
     
     
         2 . The method making use of several times of flashes to detect the distance and luminance of a target as claimed in  claim 1 , wherein a photographing key is pressed down before said flashlight emits out said flash.  
     
     
         3 . The method making use of several times of flashes to detect the distance and luminance of a target as claimed in  claim 1 , wherein said flashlight gives an appropriate luminance to said target according to a distance value and a luminance value calculated from said flash response value in said step (c).  
     
     
         4 . The method making use of several times of flashes to detect the distance and luminance of a target as claimed in  claim 3 , wherein a flashlight match program is used to control said flashlight to give said appropriate luminance to said target.